add survey link

[lisadunlap]

Why are these changes needed?

• We need to know why people are coming to the arena also what sucks about it so we can make it all better
• BIG CHANGE: Added per task and per language ranking leaderboard

Related issue number (if applicable)

Checks

• [ ] I've run format.sh to lint the changes in this PR.
• [ ] I've included any doc changes needed.
• [ ] I've made sure the relevant tests are passing (if applicable).